Influence of Density Distribution on Synchrotron Polarization Dispersion in Magnetized Interstellar Medium

Faraday rotation measure (RM) synthesis is a well-known approach originated in B. J. Burn and later developed by M. A. Brentjens & A. G. de Bruyn for studying magnetic fields. This work presents a complementary approach—the polarization frequency analysis (PFA)—allowing for the properties of the turbulent magnetic field, which are difficult to include in B. J. Burn’s original approach. Based on synthetic polarization observation of magnetohydrodynamic turbulence simulation data, we study the influence of the coupling effect between density and magnetic field on synchrotron polarization dispersion. By applying the PFA to different simulated interstellar turbulence environments, we find that the PFA technique can reveal the scaling slope of the turbulent magnetic field in the case of a weak coupling effect and can also reflect the scaling slope of the RM in the case of a strong coupling effect. Since it avoids the influence of Faraday depolarization, the PFA technique is a promising way to uncover turbulence properties using observational data from the Low-Frequency Array for Radio Astronomy and the Square Kilometre Array.